Think about it though, we are already living in a world where certain people never met, or decided not to form a band after all.

I can think of one example. In Back to the Future, didn't Marty create Rock N Roll, purely by playing such music to Chuck Berry down the phone via his cousin? Ignoring the rather long history of rock n roll itself and the time loop he created. In the future everyone listened to doo-wop instead.

where Lennon left The Beatles before they got famous and is now an acerbic minor civil servant chuntering about their MOR success (but at least has not been shot). It's a brilliant short story that Sky made into a really good one hour drama (written by David Quantick).